Simply put, responders and planners define response capability in terms of “what it is”, “how much” and “by when”. The types of capability define the “what”, for example the ability to apply dispersant to a surface slick at sea or the ability to mount an aerial surveillance operation to track and monitor the oil (and the response effort) makes up the Toolbox that responders have at their disposal to mitigate impacts of an oil spill. The IPIECA Good Practice Guide on Tiered Preparedness and Response (TPR) recognises 15 such response capabilities that could be required for any given spill scenario and is a direct output from the Joint Industry Project on Oil Spill Response following the Macondo incident in 2010.

The “how-much” introduces a quantification of the capability and it is important to recognise that capability is not just a physical measure of the hardware itself (i.e. “six skimmers”) but should include assumptions about the trained manpower to deploy, and the logistical support needed to fully enable the resource to be effective.

“By-when” implies a time element that is critical in cascading remote resource effectively. It follows that some capability is required to be immediately available to enable a local response to be initiated quickly and effectively whilst other capabilities, usually only required for larger or more complex spills, can be introduced on a longer lead-time.

To help visualise the dynamics of “what”, “how-much and “by-when”, the IPIECA Guide provides a simple model to illustrate the provision of response capability for any given oil spill risk in the form of a wheel with 15 segments representing each element of capability. Each segment is further divided to illustrate the three tiers of cascading capability (Tier 1, near the centre representing capability immediately available, Tier 2 showing intermediate capability, and Tier 3 around the periphery to indicate additional, possibly internationally-sourced capability that necessitates a longer lead time required for the largest or most complex spills.)

Planners typically use the tool when matching resources to the identified risk, as it can usefully highlight any gaps that may exist in the provision of capability.

This paper draws upon the experience of Oil Spill Response Limited (OSRL) in applying and using the Guide and the TPR wheel, both in planning and in response. Case history evidence will be used to illustrate the benefits and limitations of this industry-adopted planning and response approach.

Tiered Preparedness and Response provides a structured approach to establishing oil spill preparedness and a mechanism to build the required response effort. In the original concept, the three levels or ‘Tiers’ provide a simple structure from which oil spill response capabilities can be identified to mitigate any potential oil spill scenario.

The concept of tiered response has undergone several evolutionary developments over the last 30 years and the establishment of three fundamental stage-gates remain the bedrock of the model. Specifically, Tier 1 capabilities describe the operator's locally held resources used to mitigate spills that are typically operational in nature occurring on or near an operator's own facility. In some situations, extra resources may be required from national or regional Tier 2 providers to increase response capacity or to introduce more specialist technical expertise. It follows that Tier 3 capabilities are those globally available resources that further supplement Tiers 1 and 2. The resources held at the three tiers work to complement and enhance the overall capability by enabling seamless escalation according to the requirements of the incident. An important tenant is the cumulative nature of tiered response. The elements of Tier 1 response are supplemented by higher tier capability and not superseded or replaced by it.

Developing the TPR Wheel

Tiered response is not new and the creation of industry-owned cooperatives with substantial regional and / or international capabilities in the 1980's and 1990's paved the way for a strategic approach to resource provision. This was reflected in the original IPIECA Oil Spill Report Series on Contingency Planning (1991 and updated in 2000) which introduced the tiered response based solely upon size of spill and proximity to operations [Figure 1].

Subsequent experience has shown, however, that whist the general principles are sound, the size of spill can be difficult to define in a response and does not always relate well to the scale or complexity of the response required. In 2007 the IPIECA Oil Spill Series Report on Tiered Preparedness and Response sought to address this by introducing other factors such as the operational context, location-specific setting and legal framework considerations that have a bearing on the components of building preparedness for an effective response.

The most recent iteration of the model came after the Macondo incident (Gulf of Mexico, 2010). The response to this incident was unprecedented and led to a wholescale revaluation of technical good practice in oil spill preparedness and response based on the learnings from this landmark event. A Joint Industry Project was set up to distil and disseminate the learnings from Macondo and to this end, revise and further develop the library of industry good practice. A centrepiece of the new 24-title series is the Good Practice Guide (GPG) on Tiered Preparedness and Response (IPIECA IOGP, 2016) incorporating the latest thinking on provisioning of response capability including, for the first time, source-control as one of 15 elements of capability that may be required for any given scenario. More importantly, it gave industry the opportunity to take account of advances in communications and a kaizen approach to logistics to give greater granularity to tiered response by breaking down response capability into technique-specific elements. This approach, fully explained in the GPG, lends itself to the TPR wheel visualisation of resource capability at any given risk location. The resulting pictogram is a useful gap analysis tool that can help identify any missing elements in terms of the capability elements across the three tiers at which they may be required.

Tiered Preparedness and Response therefore provides a structured approach to establishing oil spill preparedness and a mechanism to build the required response effort. Collectively these resources combine to establish response capability and are categorised according to whether that capability is held locally, regionally or internationally, aligning with the tiers. This geographical distinction is at the core of the tiered model and enables capability to be built around the potential severity of the incident and the timeframe in which resources are needed on-scene. The tiers should only be used to define the resources available to respond to the incident and not the scale of the incident itself. Removing the link with volumetric thresholds between tiers implied in the earlier model, enables the resources required to be provisioned according to the needs of the incident and not relating to a predetermined spill volume.

Applying the model

As with any tool, it is important to first read the ‘instruction manual’, in this case the GPG referred to earlier provides important context and guidance.

A completed wheel depicting 15 elements of tiered response capability has the appearance of a three-dimensional dartboard (Figure 2). The model has around 50 possible coloured sectors and segments arranged in concentric circles and can appear mesmerising and bewildering to the uninitiated. It is also important to not read too much into the hypnotic symmetry of a completed wheel. It can be tempting to look for prescriptive answers in terms of how many skimmers, delivered by when, to provide the optimum response to a given scenario, and expecting this level of specificity can lead to disappointment.

The model is increasingly being used as a contingency planning tool to help visualise the whole scope of resource provision (and any gaps therein) both in a qualitative and temporal sense. It is, however, much more than this. It can be used as a catalyst for preparedness discussions and used in exercise settings to demonstrate and confirm the timescales and escalation of various elements of tactical response provision for a given scenario. Furthermore, it can be tailored and adapted to give a more precise time scale to when capability can be brought to bear. We will now discuss some of the experiences of using the model that Oil Spill Response Limited (OSRL) and its Members have undertaken in the application of the model to visualise and enhance preparedness discussions.

Case Study #1: Putting ‘Tiered Preparedness and Response’ into Context – Response Integration between Tier 2 and Tier 3 Oil Spill Response Organisations.

Implicit to the TPR model is a seamless integration of resources across each Tier – 1, 2 and 3; however, this is not readily achieved in practice, given the challenges of geography, maturity and state of preparedness at each location, legislation and even national sovereignty. As an international industry-funded Tier 3 cooperative, OSRL recognises these challenges and works to overcome them as part of their core mission.

To this end, the engagement between OSRL and local, or regional Oil Spill Response Organisations (OSROs), is crucial; equally important is the outreach effort to inform governments and local industry.

Following a series of engagements with industry-funded OSROs based in East Asia, OSRL spearheaded the formation of the Regional Industry Technical Advisory Group (RITAG), which served to mirror aspects of the Global Response Network (GRN)1, but with a regional focus. This is in recognition of the challenges that will be encountered, but are often overlooked, when working in a culturally and politically diverse region.

Officially established in 2010, RITAG provides a platform to facilitate the sharing of technical knowledge and oil spill response experience, promote industry good practice, and expedite a tiered response for the industry. Currently, the group comprises eight OSROs, with OSRL as the permanent secretariat (since 2018).

In parallel, OSRL, has over the years, developed bi-lateral Memorandums of Understanding (MoU) with various OSROs, including those in the RITAG membership, based on the principles of technical cooperation and joint response, in the interest of common Members; examples include the Australian Marine Oil Spill Centre (AMOSC), Petroleum Industry of Malaysia Mutual Aid Group (PIMMAG) and China Offshore Environmental Service (COES). Key provisions common to the MoU with each organization, where practicable, include:

  • 1) Development of protocols for technical and logistical cooperation, and assistance in the event of an oil spill in (said country where the Tier 2 OSRO operates);

  • 2) Development of an operational integration plan, including the exchange of personnel;

  • 3) Conduct of joint training, table-top exercises and simulations;

  • 4) Conduct of joint field deployment exercises;

  • 5) Recognition of the importance of ‘tiered response’, and agreement to jointly represent the value and benefits of TPR to both industry and regulators

Particular success was achieved in the effort to enhance response integration between OSRL and COES, a subsidiary of the state-owned China National Offshore Oil Corporation (CNOOC) and the largest Tier 2 OSRO in China.

Following the signing of the MoU in 2014, personnel exchange between OSRL and COES commenced in 2015, with strides being made between 2016 and 2018 to enhance the working relationship between two organisations; this culminated in the participation of OSRL in the largest at-sea emergency drill jointly conducted by the three state-owned oil and gas companies in China, testament to the integration of Tier 3 resources beyond national boundaries. This was a first, for both OSRL and COES.

A brief timeline elaborating the journey taken by OSRL to enhance cooperation with COES is provided in Table 1 below:

Evidently, successes in the cooperative effort between OSRL and COES would be attributed to continual engagement - a cornerstone which supports the application of the TPR framework in oil spill preparedness and response. In particular, such cooperation is essential to the breaking down of barriers and allowing decision makers to frame an incident around the type of resources required – responders (people), specialist equipment, additional support - and how these should be cascaded, to put TPR to the greatest effect.

While the personnel exchange only addressed the subject of ‘people’ resources, it could be argued that well-trained and competent personnel underpins the ability to effectively deploy each of the 15 capabilities on the TPR Wheel; additionally, the relative ease to relocate people across borders, versus equipment, must be taken into perspective, against the constraints of complicated customs and immigration procedures encountered in most of East Asia. The engagement model presented in this case study offers great merit and opportunities to further enhance the working relationships between OSROs.

Case Study #2 – Using the TPR Wheel as the basis for a readiness review

As part of OSRL's Service Level Agreement (SLA) its Members are entitled (and encouraged) to participate in an Annual Preparedness Review (APR). This can be completed in a number of ways for example through OSRL's participation in an exercise, the delivery of a presentation to the emergency response team to explain the notification and mobilisation process but also through a “Ready Check” of the Members' oil spill response arrangements.

The Ready Check was developed based on OSRL's extensive experience in the field of oil spill response and serves as a useful checklist for reviewing the management and operational factors which will govern the effectiveness of a spill response. In the United Kingdom, there is clear guidance which describes the expectation from the regulators on operators within the UK Continental Shelf (UKCS) in relation to their emergency spill management and the resources that operators have available. The evolution of TPR through the introduction of the TPR wheel is complimentary to this guidance but has also offered a structure to describe and review the response arrangements in more detail. Therefore, when the TPR good practice guidance was issued by IPIECA/IOGP, OSRL identified an opportunity to use the TPR Wheel as a tool to complete an interactive workshop with OSRL UKCS members to review their current oil spill arrangements Regular member events are held in Aberdeen by OSRL, most taking the format of workshops; this format best suited the TPR session. Large posters of the TPR wheel were printed on plastic coated paper (to ensure that the posters are reusable) and attached to flipchart stands. Participants could then annotate the posters based on details regarding their own operations and risks.

One of the key takeaways from this session was the importance of having the right people in the room. To ensure the greatest usefulness and success participants needed to have a very good understanding of their operations, and therefore risks, but also understand the emergency response arrangements in place. The session needed to be facilitated by people who were familiar with the requirements of each of the techniques that comprise the TPR wheel in all three facets of capability, namely; trained responders, dedicated equipment and additional support.

Outcomes of this session were clear, actionable tasks to either confirm, or put in place additional requirements, an example of this is planning for shoreline response. In the UK the Local Authorities have responsibility for a shoreline response and the guidance to operators for shoreline plans is limited to those that have installations within 40km of the shore or a pipeline which comes ashore. Through the workshop it was identified that some operators had actionable tasks complimentary to the regulatory regime to understand and document an example of this is the consideration or additional of notification parties to checklist in their plans if there was the actual or potential for a shoreline impact from one of their operated assets.

Case Study #3: Using the Tiered Preparedness & Response Framework to Support Incident Management Decisions

Oil spill preparedness should include coverage of worst credible case oil spill scenarios in the planning process, however there may be some scenarios where the required level of preparedness may not meet the response scenario being faced. Such an example was faced by OSRL when mobilised to support an incident response for a previously abandoned well which was no longer considered an active risk for the responsible party.

In support of this incident OSRL used the TPR framework in conjunction with NEBA / SIMA justification to help drive dynamic incident management decisions early in the response phase. The TPR wheel was used as a guide to appraise each response technique and its suitability to be incorporated into the evolving response strategy. Since no specific planning had been completed for this scenario the TPR wheel was used as a framework to explore the existing capabilities and to identify gaps that would hinder the implementation of the selected strategy.

Initially, in-field resources were deployed to respond to the incident while additional resources were brought in from regional and international sources. In this case, resources comprising equipment, trained personnel and additional support were cascaded and phased into response over a period of approximately five days. This phased approach appropriately married incoming specialised resources with locally available logistics.

A key consideration in this case was the ability to communicate a compelling response strategy and build of capability from various locations using the visual and interactive TPR Wheel. This message was communicated to both technical and non-technical stakeholders. Briefings were held with Crisis Management Team (CMT) members and local government officials to obtain authorisation to mobilise resources and obtain access to sensitive sites. The simple Microsoft Excel tool allows the user to quickly create a graphical qualitative representation of the capability requirements, which aids comprehension and identify gaps.

Case Study #4: Evolution of the TPR Wheel

Shell's Oil Spill Expertise Centre (OSEC) in collaboration with OSRL recognised the potential that the TPR wheel has as a benchmarking tool for a global enterprise with numerous sites, a variety of operations and a potential for varying complexity of spill responses. Recognising that subjectivity would hinder a clear and fair assessment across business units worldwide, an alternative way to assess tiered capability needed to be considered.

The Challenge of Measurement

As a standalone visual representation, the TPR wheel was, by definition, purely illustrative. The size of each segment merely indicating the capacity provided from each Tier. To move the wheel from a symbolic illustration of the TPR framework to a usable representation of specific operations became a challenge of measurement. Each location and operation has its own characteristics, with specific preparedness needs driven by its unique setting and operational factors. These variables mean that the same operation conducted on two different sites may have completely different capacity requirements, or even different required capabilities. Therefore, trying to establish a measurable tiered optimum performance unit was not possible, as it would look different for every site assessed. Additionally, one standardised unit of capacity would not be possible for each area of capability, with metres or boom, volume of dispersant and number of trained personnel naming just a few of the relevant performance measures.

The additional challenge when adding scale to the TPR wheel occurs due to subjectivity and consistency of application. Subjectivity from assessor to assessor; and subjectivity from site to site. What could be deemed as strong Tier 1 capability on one site may be considered as insufficient capability on another, depending on the assessor's justification based on NEBA/SIMA. However, this may not have been depicted clearly in the segment of the TPR wheel.

In an attempt to tackle this subjectivity, it was first and foremost required to identify a unit of measure that could be calibrated across all sites, all scenarios, and used by assessors from all of backgrounds. A unit of measure similar to a mathematical constant was needed; a value (or term, in this case) that is by definition unambiguous and common to all response scenarios.

‘Time’ as a standard unit of measurement

As previously mentioned, one can summarise capability simply as how much of something is needed by when and with the challenges around a measure of capacity laid out above, the remaining variable of ‘by when’, or ‘time’ was considered. More specifically, the time it takes for the resources at each Tier to be integrated into operations and thus starting to have a positive impact during response. Time, as a unit, transcends capacity as a universal measure of performance for all types of capability.

Using time in this assessment methodology, the response clock for each segment of the TPR wheel is started when the request for mobilisation is made. This enables the viewer to clearly understand how long a particular option, be that at Tier 1, 2, or 3, will take to be integrated into the response.

Mobilisation is at the centre of the TPR wheel depiction, replacing the original position held by IMS. This change was required in order to fairly assess time to deliver capability, but also to recognise IMS (or any spill management framework) as a standalone capability required to manage the incident. A benefit of this change is the overlying message that mobilisation of resources should not be delayed, as time to achieve a particular segment of the TPR wheel may be considerable.

This methodology offers another dimension to a capability assessment: The ability to assess when finite resources will run out; or when additional resources would be required. A classic example is dispersant. If dispersant operations at Tier 1 will run out of dispersant within 12 hours, but Tier 2 dispersant supply will not be available for at least 48 hours from mobilisation, there is a clear capability gap in dispersant operations.

Another change required was the separation of equipment and trained personnel required to deliver the relevant segment of the TPR wheel. Capability is, of course defined in the good practice guidance as a combination of trained personnel, specialised equipment and other support. In this time-based assessment method, trained personnel are assessed separately, since equipment integration times are often longer than the integration of the trained staff into the response structure.

The final addition to the method is a graphical display in the form of rings, depicting key moments in the response timeframe; predicted shoreline impact, the window of opportunity for effective use of dispersants and predicted national boundary crossing. These key moments in time are essential to be highlighted, as their consequences will affect response objectives and strategies.

Value in Preparedness and Response

As an assessment tool, its use brings benefits in both the preparedness phase and the response phase. In preparedness, it can be used as a planning tool, or even an auditing tool to assess current capability, and capability strengthening required depending on business unit oil spill risk profile. It enables a pragmatic conversation regarding capability that can be measured in time.

During the development stages, two versions of the TPR wheel graphical display were created. A simplified version (graphically similar to the original TPR wheel) and a detailed version of the TPR wheel. An example of each can be seen below in Figures 5 and 6.

In response, it can be used as a static reference, a visual aide to indicate time to integrate into response for all capabilities. Particularly for response, OSEC has developed a poster (Figure 7) that can be displayed in the business units' emergency management rooms. The poster is the final product of the capability assessment.

In addition to the TPR assessment, the poster offers more information;

  • What resources were considered at each Tier for each capability

  • What capabilities are feasible to be executed by in-country resources, which will need regulatory permission, and which do not apply to the scenario

  • The risk of external factors being a constraint to response

  • Capabilities that can be utilised prior to shoreline impact

  • Response stalling/bottleneck factors identified as part of the assessment

  • Requesting resource mobilisation.

Also, of great benefit to an Incident Management Team, is the pre-emptive consideration of what response enablers are likely to be response limitations and constraints. These factors, also known as ‘other support’ in TPR parlance, are essential to deliver the various response capabilities, but without being specifically part of the capability itself. For instance, vessel availability, visas, fuel, lifting equipment, in-country logistics, accommodation etc., constraints in these areas could negatively impact the effectiveness of any response.

The implementation of this form of TPR assessment is still in its infancy, but feedback from the stakeholders is encouraging. The simple and concise visual layout and timescale for Tiered capability assessment are often mentioned as a positive introduction and a step forwards in critical information availability. The next step could be the development of a dynamic TPR tool that can be populated and maintained to visualise progress of resource deployment in the field. This dynamic assessment would potentially be the ultimate response timeframe display to the Incident Management Team.

The case histories provided here offer a glimpse into the varied ways that the Tiered Preparedness and Response has been implemented since the release of the GPG in 2015. The publication, which introduced the now iconic TPR Wheel, was created to communicate the enduring principles of TPR but also to reflect the ongoing evolution of Industry's approach to building robust preparedness and response frameworks. The fundamental principles of TPR outlined below still resonate today, but it is recognised that the tools and techniques and overall awareness of the holistic nature of response continue to develop.

  • be commensurate with the assessed risk

  • encourage collaboration, mutual assistance and integration of shared resources

  • be fully scalable through a mechanism of escalation and cascaded from the resources held through the three tiers

  • be tested, maintained and assured as part of a defined preparedness framework

  • employ the most appropriate response options reflecting NEBA

The common theme emerging from each case study is how the TPR Wheel and GPG has helped to catalyse conversation and drive improvement, not least through visually representing the principles above, but also through the natural curiosity and interest generated through the novel representation of the mature model. Case Study 1 exemplifies the importance and commitment to collaboration and mutual assistance so that resources can be elegantly integrated during a response via appropriate mechanisms of escalation. Case Study 2 references the importance of providing a level of assurance through testing preparedness measures through dialogue and engagement. Case Study 3 illustrates how flexible the model can be where, in the absence of appropriate preparedness measures, a successful response can still be mounted through the diligent application of NEBA. Finally, Case Study 4 illustrates how progressive thinking and a desire for continuous improvement is lifting the TPR wheel off the page to facilitate a deeper application of the principles of TPR and creating new insights for improved preparedness. This final case study takes the evolution of the TPR Wheel to the next logical step through the application of a universal unit of time to further reinforce the definition of response capability in terms of; ‘what it is’, ‘how much’ and ‘by when’. This honest and transparent assessment of timely access to Tiered capability commensurate with the assessed risk then allows planners to identify gaps and then work to plug them by ensuring that the right resources are where the need to be, when they are needed.

Tiered Preparedness and Response and its principles remain evergreen, with the overall aim to ensure that the right resources are available in the right place at the right time. The advent of the TPR Wheel was itself an evolution borne of Macondo and the subsequent commitment from Industry to share, learn and improve. In this sense the inevitable ongoing evolution of the TPR Wheel is recognised, and indeed welcomed, as a natural response to our changing Industry, external environment and understanding. This latest evolution is admittedly in the early conceptual stage, but already the potential benefits have begun to be realised by offering a different lens from which to assess preparedness. It must also be recognised that while beneficial, any evolution of the original TPR Wheel should not replace the existing practices of risk assessment and contingency planning, but to support and complement them.

Predicting the next evolutionary steps for the TPR Wheel and the application of Tiered Preparedness and Response model is difficult, but history has shown us that the foundational principles are strong yet flexible enough to adapt to change. In 2015, the ‘simple’ illustrative TPR Wheel icon created a demand for scale, and early indications suggest that ‘time’ may have answered this call. Future pleas may be for additional levels of detail in specific areas of capability such as Wildlife Response, Source Control, or IMS, but again, the potential to duplicate the content of contingency and tactical response plans must be recognised and resisted, unless clear value can be added. Other areas of detail not covered in the TPR wheel, include the importance of balancing capability so that equipment, trained personnel and other support are suitably balanced. Finally, as a framework for cascading capability from local, regional and international sources, one must also recognise the instrumental importance of a strong logistical supply chain as the golden glue that will always hold this TPR wheel together.

1 The Global Response Network (GRN) consists of specialist oil spill response organisations from around the world. Its remit is to share information, improve spill response performance and to provide centres of expertise in spill preparedness, response and recovery techniques.

Tiered Preparedness and Response: Good practice guidelines for using the tiered preparedness and response framework [online]